A three-storey building with a private school inside collapsed while classes were in session, Wednesday, in the capital, Lagos.

The structure also housed offices, shops and residential units. The incident took place near Itafaji market on Lagos Island at around 10:00am local time (0900 GMT). The building was about 30 years old and wasn't maintained. Lagos Emergency Management Agency's Tiamiyu was sceptical that the building met the necessary safety standards. Some witnesses estimated that there were as many as 100 children in the school building at the time of the collapse.Workers have pulled more than 40 people, dead and alive, from the ruins.

The statement by National Emergency Management Agency spokesman Ibrahim Farinloye does not say how many of the dead or rescued are children but Lagos governor Akinwunmi Ambode says at least 25 children have been rescued. Hundreds of people stood in narrow streets and on rooftops of rusted, corrugated metal, watching rescue efforts. Rescue efforts were expected to continue through the night Wednesday. Bright lights were brought in to allow search efforts to continue. Building collapses are all too common in Nigeria, where new construction often goes up without regulatory oversight. Over 100 people died in 2016 after a church roof collapsed in south of Nigeria. Lagos is one of the fastest growing cities in Africa.